Filled-bag stacking palletizer



'7 Sheets-Sheet 1 Filed Feb. 7, 1966 NGE y 1968 R. T. SHEEHAN 3,381,828

FILLEDBAG STACKING PALLETIZER y 1968 R. T. SHEEHAN 3,381,828

FILLED-BAG STACKING PALLETIZER Filed Feb. '7, 1966 7 Sheets-Sheet 1INVENTOR ROBERT T. SHEEHAN ATTORNEYS R. T. SHEEHAN May 7, 1968FILLED-BAG STACKING PALLET [ZI'JR 7 Sheets-Sheet 4 Filed Feb.

R. T. SHEEHAN May 7, i968 FILLED-BAG STACKING PALLETIZER 3N @mm Q 01Filed Feb.

ay 7, 1968 R. T. SHEEHAN 3,381,328

FILLED-BAG STACKING PALLETIZER Filed Feb. 7, 1966 7 Sheets-Sheet 6FIG.I5 I

/6 ATTORNEYS R. T. SHEEHAN May 7, 1968 F BAG STACKING PALLETIZER ILLED-7 Sheets-Sheet 7 Filed Feb. 7, 1966 ON 0E INVENTOR ROBERT T. SHEEHANATTORNEYS Unit ABSTRACT OF THE DISCLOSURE This automaticfilled-bag-stacking palletizer automatically receives filled bags from abag feeding conveyor coupled thereto and deposits and stacks the filledbags on a turntable in one of a number of predetermined patterns insuccessive tiers of three, four or five bag patterns. When the pallethas been fully loaded, a pallet dispenser then automatically pushes anempty pallet onto the turntable while causing the empty pallet tosimultaneously ejected the loaded pallet onto the loaded palletreceiver. The stacking conveyor is also mounted on an elevator whichraises and lowers it to different levels of stacking.

During the stacking operation, the stacking conveyor is automaticallyshifted relatively to the turntable both horizontally by laterallyreciprocating the carriage on which the stacking conveyor is mounted andvertically by the elevator into successive parallel positions in timedrelationship with the rotation of the turntable step-by-step through90-degree intervals. The elevator is optionally provided with means forreciprocating the stacking conveyor longitudinally to extend and retractthe stacking conveyor in order to stack the bags in an oblong patternupon an oblong pallet when it is desired to use an oblong pallet.

In the accompanying drawings:

FIGURE 1 is a diagrammatic top plan view of an automatic filled-bagpalletizer, according to the invention, with the hydraulic pipingomitted for simplicatiOn, after having stacked bags to an odd-numberedtier of a stack of bags in a four-bag pattern;

FIGURE 2 is a top plan view of a pallet loaded to an even-numbered tierof a four-bag pattern;

FIGURES 3 and 4 are top plan views of pallets loaded with bags stackedto even-numbered tiers of three-bag and five-bag patterns, respectively;

FIGURE 5 is a vertical section, mainly in side elevation, of thefeeding, stacking and turntable units, taken along the line 5-5 inFIGURE 1;

FIGURE 6 is a diagrammatic front elevation of the automatic bagpalletizer shown in FIGURE 1, looking in the direction of the arrows 6-6therein;

FIGURE 7 is a side elevation, partly broken away, of the elevatingstacking conveyor carriage with the stacking conveyor shown in itslowermost position in dotted lines upon a larger scale than is shown inthe central portion of FIGURE 5;

FIGURE 8 is a rear elevation of the stacking conveyor carriage shown inFIGURE 7, with the stacking conveyor shown in dotted lines;

FIGURE 9 is a side elevation of the boom conveyor, with the housingthereof removed, as shown in dotted lines in FIGURE 7, with the adjacentportions of the carriage shown in dotted lines;

FIGURE 10 is a top plan view of the stacking conveyor shown in FIGURE 9;

FIGURES l1 and 12 are rear and front ing in the direction of the arrows11-11 and respectively in FIGURE 9;

FIGURE 13 is a top plan view of the turntable unit which carries thepallets and receives the filed bags from the stacking conveyor;

elevations look- States Patent 0 FIGURE 14 is a front elevation of theturntable units, looking in the direction of the arrows 14-14 in FIG-URE 13;

FIGURE 15 is a fragmentary side elevation f a spring-mounted yieldingroller;

FIGURE 16 is a vertical section taken along the line 16-16 in FIGURE 15;

FIGURE 17 is a side elevation, partly in section, of the pallet ejectorin the pallet dispenser of FIGURES 1 and 6, with the central portionomitted to conserve space and enable a showing of the parts on a largescale;

FIGURE 18 is a top plan view of the pallet ejector shown in FIGURE 17;

FIGURE 19 is a cross-section, upon an enlarged scale, taken along theline 19-19 in FIGURE 17; and

FIGURE 20 is a diagrammatic view of the hydraulic circuit for theautomatic bag palletizer with the valveactuating solenoids and electricpump-driving motor.

General arrangement Briefly summarized (FIGURES 1 and 6), the automaticfilled bag palletizer, generally designated 20, of the present inventionincludes a bag feeding conveyor 22 which receives the filled bags B froma fixed filling station 24, such as from a bag filling machine, anddelivers them bag by bag to the inlet end of a stacking conveyor 26coupled therewith. The stacking conveyor 26 conveys and flattens thefilled bags and drops them one-by-one upon a turntable unit 28 whichrotates in timed relationship therewith after the stacking conveyor 26has moved stepby-step horizontally and vertically, as indicated by itsdotted line positions in FIGURES 1 and 6. The bags B are deposited uponempty pallets P from a pallet dispenser 30 which also operated in timedrelationship to the previously-mentioned units 26 and 28 and which atthes ame time causes the feeding of each empty pallet P to eject aloaded and stacked pallet S with its load of bags B onto a loaded palletreceiver 32, whence the loaded stacked pallets S are removed byconventional fork-lift trucks, one of which is indicateddiagrammatically at T, and conveyed either to transport vehicles (notshown) or to storage places in a warehouse.

The filled bags B are also flattened while being conveyed within thestacking conveyor 26, so that as many as eight tiers of bags 13 may beaccommodated on a single pallet P without toppling, and, furthermore, sothat loaded stacked pallets S may in turn be stacked one upon anotherwithin the warehouse, thereby conserving storage space and reducing thecost of storage. In the warehouse, as many as four loaded stackedsix-tier pallets can be placed on top of one another up to an overallheight of 16 feet by a suificiently high loading fork lift truck. Thehydraulic pressure fluid by which the various units are actuated issupplied from a hydraulic power unit, generally designated 34. In thecentral portion of FIGURE 1, the order of stacking of the bags B isindicated by their numbers B-l, 3-2, 13-3 and 13-4. It will be observedfrom FIGURES l to 4 inclusive that the bags B are stacked in diiferentsequences in even-numbered and odd-numbered tiers so that the bags ofone tier overlap the junctions of bags of adjacent tiers in order toprevent slippage and consequent toppling.

Bag-feeding conveyor The bag-feeding conveyor 22 (FIGURE 5) is movablymounted upon a platform which in turn is mounted on the floor 42 of thebuilding in which the stacking and palletizing operations are takingplace. The bag-feeding conveyor 22 includes a step-ladder-shaped A frame44 on the bottom of which are mounted swivel casters 46 and on the topof which a lower pivot bearing 48 is mounted. The latter through a pivotshaft 50 cooperates with an upper pivot bearing 52 mounted on the bottomof the upper end of the feeding conveyor housing 54. Mounted upon andjournaled in the housing 54 at opposite lower corners thereof are idlerand drive pulleys 56 and 58 respectively carrying a conveyor belt 60 offlexible material, such as rubber. The upper and lower courses of theconveyor belt 60 are supported by idler rollers 62 and 64 respectively.The drive pulley 58 is driven by a belt 66 from a motive pulley 68driven by a rotary hydraulic motor 70. Pivoted at 69 to the oppositeside Walls of the housing 54 are swinging bag guide plates 71 connectedto adjustment rods 73 slidable in spacedly-drilled guide sleeve 75welded to the side walls of the housing 54 and adapted to receiveangle-locking pins 77. Secured as by welding to and depending from thehousing 54 at its lower forward corner beneath the drive pulley 58 is anupper pivot bracket 72 which is drilled centrally to receive a pivot pin74.

Palletizing stacking conveyor The pivot pin 74 extends downwardlythrough one of a series of longitudinally-spaced holes 80 in a bearingplate 81 mounted on a lower pivot bracket 82 projecting rearwardly fromthe lower rearward corner of the supporting frame 84 (FIGURES 9 and of abag-depositing boom conveyor, generally designated 86, forming a part ofthe stacking conveyor 26. As previously stated, the boom conveyor 86 israised and lowered in order to perform its function of depositing thefilled bags B upon the turntable unit 28, and, for rectangular or Oblongpallets, also reciprocates longitudinally, as in stacking bags in thefive-bag pattern of FIGURE 4. As a consequence, as explained more fullybelow in the descritpion of the operation of the invention, the frame 44of the bagfeeding conveyor 22 is moved back and forth as well as rotatedthrough a partial revolution in response to the motions of the boomconveyor 86. The latter also tilts the housing 54 around the pivot shaft50 as it rises and falls, thereby maintaining the lower forward end ofthe feeding conveyor 22 constantly in close proximity to the rearwardend of the boom conveyor 86. The supporting frame 84 includes parallellongitudinal inverted T-members 87 composed of angle bars secured backto back and upon which it rests (FIGURE 11).

Deferring for the moment the detailed description of the boom conveyor86, it will be observed from FIG- URES 5, 7 and 8 that the boom conveyor86 is supported and moved upward and downward as well as forward andrearward upon a tower-like carriage 88 which in turn is mounted forlateral hor' ontal travel up n parallel channel V-tracks 90 mounted onand secured to the floor 42. For this purpose, the bottom of the frame92 carries grooved wheels 94 which ride on and move laterally along thetracks 90. The tracks 90 are interconnected at their opposite ends andintermediately by cross members 96. The cross members 96 at theirmidpoints are interconnected by a channel member 98 (FIG URE 7).

Mounted on the channel member 98 is a cylinder 100 of a reciprocatoryhydraulic carriage motor 102 containing the piston head (not shown) of apiston 104. The piston 104 carries a clevis 106 pivoted at 108 to adepending bracket 110 which in turn is secured to the under side of thebottom of the frame 92 of the carriage 88. As a consequence, admissionof pressure fluid alternately to one end of the cylinder 100 and itsrelease from the opposite end causes the piston 104 and consequently thecarriage 88 to move back and forth laterally relatively to the tracks90. Secured to the tracks 90 (FIGURE 7) are upstanding brackets 112carrying holddown rollers 114 engaging holddown roller tracks 116secured to the base of the frame 92 (FIGURE 8). These holddown rollers114, as their name indicates, hold down the carriage 88 and prevent itfrom jumping its tracks 90 as it moves to and fro along them.

The frame 92 of the carriage 88 includes four inwardly-facing verticalchannel guide posts 116 (FIG- URES 7 and 8), opposite pairs beinginterconnected by longitudinal cross members 118. Bolted to theright-hand pair of cross members 118, looking from the rear in FIGURE 7,is the cylinder 120 of a vertical reciprocatory hydraulic lift motor122, the piston 124 of which (FIGURE 7) is pivoted at 126 to a cross bar128, the opposite ends of which are welded or otherwise secured tovertical channel slides 129 which are slidable in the right-hand pair ofchannel guide posts 116. Midway between the left-hand pair of posts 116there is mounted the cylinder 130 of a vertical reciprocatory hydraulicmotor 132, the lower end of which is pivotally mounted at 134 on theframe 92. The hydraulic motor 132 is, except for this pivotalself-aligning mounting of the lower end of its cylinder 130, otherwiseof the same construc tion and has the same connections as the hydraulicmotor 122, and its piston (not shown) corresponding to the piston 124,is similarly pivoted to a cross bar (not shown) similar to the cross bar128, similarly secured to vertical channel slides like the slides 129but which are Slidable in the left-hand pair of channel guide posts 116.

Each of the cross bars 128 carries two pairs of spaced depending ears136 between each of which is rotatably mounted a sprocket 138. Trainedover each sprocket 138 is a sprocket chain 140, the outer end of whichis anchored to one of the uppermost cross members 118. The opposite endsof the sprocket chains 140 are anchored to a vertically-movable elevatorframe 142 (FIGURE 8) which is likewise guided for vertical motionbetween the vertical channel posts 116. As a consequence, when hydraulicpressure fluid is admitted to the lower ends of the cylinders 122 and132, and discharged from the upper ends thereof, the pistons 124, crossbars 128 and sprockets 138 are pushed upward, thereby pulling thesprockets chains 140 upward and moving the elevator frame 142 upward,guided by the channel slides 129 within the channel posts 116. By thisarrangement, the elevator frame 142 is made to rise higher than theposts 116, and twice the length of stroke of the pistons 124.

Boom conveyor Longitudinally slidably mounted upon the elevator frame142 for forward and rearward motion relatively thereto are the invertedT-members 87 of the supporting frame 84 of the bag-depositing boomconveyor 86, which has an enclosing housing 144 composed of top, bottomand side plates (FIGURE 5). Such motion is brought about by a horizontalreciprocatory hydraulic boom conveyor motor 146 (FIGURES 9 and 10'), therearward end of the cylinder of which is pivotally mounted at 148 on theelevator frame 142, whereas the forward end of the piston thereof ispivotally connected at 150 to the bottom of the boom conveyor housing144. By supplying hydraulic pressure fluid to one end of the hydraulicmotor 146 and discharging it from the other end, the boom conveyor 86may be caused to move longitudinally forward and rearward relatively tothe elevator frame 142. This longitudinal motion, however, is ordinarilyinactive when the machine 20 is stacking bags B in a square pattern upona square pallet, as in FIGURES 1 to 3 inclusive, and is brought intoplay when stacking an oblong pattern of bags upon an oblong pallet, suchas the five-bag pattern shown in FIGURE 4.

The support frame 84 of the boom conveyor 86 consists of an elongatedopen-centered ca ge-like framework of steel angle members and channelmembers, including the parallel inverted T members 87, and has alongitudinallyelongated opening 152 in the forward lower end thereof(FIGURE 9) for the ejection of the bags B upon the pallet P. Alsomounted forwardly and rearwardly of the opening 152 are twolaterally-extending longitudinallyspaced facing channel guide members154 which slidably support the bag release gates described below.

Rotatably mounted on the rearward end of the boom conveyor supportingframe 84 is a lower conveyor belt drive shaft 156 carrying a lowerconveyor belt drive pulley 157 and a rearward driving drum 158 overwhich is trained a lower endless conveyor belt 160. The latter at itsforward end is trained around an idler drum 162 which is rotatablymounted on the shaft 164 adjustably secured to the framework 84 forbelt-tightening purposes. Intermediately, the upper course of the lowerconveyor belt is supported by longitudinally-spaced parallel upperrollers 166, the lower course being supported by similar rollers 168arranged in staggered relationship to the upper rollers 166 (FIGURE 9).

Rotatably mounted on top of the boom conveyor supporting frame 84 is anupper conveyor driving drum 170 on a shaft 172 carrying an upperconveyor belt drive sprocket 774 (FIGURE 9). Also rotatably mounted onthe top of the frame 84 is an idler sprocket 176. Trained around thedrive sprockets 157 and 174 and the idler sprocket 176 and also around apower output sprocket 178 is a sprocket chain 180. The power outputsprocket 178 is keyed or otherwise drivingly secured to the output shaft180 of a speed reducer 182 which, as shown in FIGURE 9, is driven by arotary hydraulic motor 134 through a v V-belt 185 (FIGURE 11).

Rotatably mounted near the forward end of the boom conveyor supportingframe 84 is an idler drum 188 (FIG- URE 9), and between it and theconveyor driving drum 170 are rotatably mounted thrust rollers 190disposed on longitudinally-spaced parallel axes of rotation. Trainedaround the drums 170 and 188 and beneath the thrust rollers 190 is anupper endless conveyor belt 192 spaced vertically away from the lowerconveyor belt 160' so as to provide a bag passageway 194 therebetween.

Also mounted on top of the boom conveyor supporting frame 84 is aninverted U-shaped auxiliary frame 196 within which is mounted avertically-movable slide 198. Rotatably mounted on the lower end of theslide 198 is a belt flattening roller or drum 2011. The slide 198 ismoved upward or downward vertically in its auxiliary frame 196 by screwshafts 2112 threadedly engaging the top of the auxiliary frame 196 andcarrying hand cranks 204.

Mounted in longitudinally-spaced parallel relationship on the oppositesides of the boom conveyor supporting frame 84 are bushings 206 (FIGURESl0 and 11). Slidably mounted within the bushings 206 are stub shafts208, the inner ends of which, within the housing 144, are connected toflexible elongated narrow bag guide plates 210. The rearward ends of theguide plates 210 r are flared outwardly at 212 to facilitate entry ofthe bag. Consequently, by moving the shafts 2118 inward or outwardwithin their respective bushings 2116, the bag guide plates 210 may bebrought closer together or moved farther apart in accordance with thesize of the bags being stacked at that particular time. The bushings 206are provided with holes 214 to receive angle pins 216, the shanks ofwhich pass downward through aligned holes in the shafts 208 for lockingthe latter in their adjusted positions.

Mounted on top of the forward end of the boom con veyor frame 84 (FIGURE10) is a reciprocatory gateoperating hydraulic motor or cylinder 218,the piston 220 of which carries a cross head 222 to which areself-aligningly pivoted the inner ends of links 224, the outer ends ofwhich are self-aligningly pivoted to the ends of yokes 226 loosely androtatably mounted on parallel shafts 228, the outer ends of which areconnected to the upper ends of bent or bellcrank levers 230 pivotallymounted on brackets 232 welded or otherwise secured to the top of theboom conveyor frame 84.

Pivotally connected to the lower ends of the bent levers 230 arebrackets 234 which are welded or otherwise fixedly secured to the outerends of oppositely-moving gates 236. Rotatably mounted on the innercorners of the gates 236 are rollers 238 (FIGURES 9 and 12) which rollback and forth in the channel guide members 154 as the gates 236 areopened and closed by the swinging of the bent levers 230 in response tothe reciprocation of the piston 220 and cross head 222 of the hydraulicmotor or cylinder 218. The upper brackets 232 and lower brackets 234 areinterconnected by shafts 240 and 242 respectively which the bent levers231 pivotally engage (FIGURE 9). Sufiicient clearances are providedbetween the outer portions of the gates 236 and the boom conveyor frame84 to permit such outer portions to rise without interference as theyare pulled outward and upward by the lower arms of the bent levers 230.Pivotally mounted as at 244 on the upper outer end of the boom conveyorframe 84 (FIGURE 9) is a swinging depending plate 246 which operates alimit switch 248 mounted on the end of the frame 84 when a bag B of theconveyed and stacked material collides with the swinging plate 246before being dumped by the opening of the gates 236 in response to theaction of the limit switch 248.

Pallet-receiving turntable unit The turntable unit 28 (FIGURES 12 to 15inclusive) is mounted in front of the boom conveyor 86 and below theopening 152 therein. It consists of a supporting base 250- which in turnis bolted or otherwise secured to the floor 42 (FIGURE 13). Thesupporting base 250 is preferably of hollow steel construction. Mountedat 90-degree inter vals around the top of the base 256 are wheel forks252 rotatably supporting the axles 254 of wheels 256. Also rotatablysupported within the base 250 is a rotary vertical shaft 258 placed atthe center of a hollow inverted cupshaped turntable 260 having acircular top wall 261 and a depending cylindrical side wall 263. Theshaft 258 is seated in a socket 262 in a block 264 bolted or otherwisesecured to the under side of the top wall 261 of the turntable 260.Secured to and rising from the top of the turntable 260 are two pairs ofelongated parallel plates, namely a pair of outer plates 266 and a pairof inner plates 268, the latter having flared outer ends 270. The outerand inner parallel plates 266 and 268 are drilled at closely-spacedintervals to receive the axles of multiple rollers 272 arranged in twosets spaced apart from one another by the inner plates 268.

Mounted at one end of the pathway plates 273 between the inner plates268 is a spring-loaded roller unit 274 (FIGURES 13, 14 and 15) arrangedto project slightly above the level of the tops of the rollers 272. Theroller unit 274 consists of a roller 276 loosely and rotatably mountedupon a shaft 278, to the opposite ends of which are bolted angle plates28% movable up and down in cupshaped retainers 282 and urged upward byhelical compression springs 284. A slotted guide plate 286 is mounted onthe opposite side of the spring 284 from the retainer 282. As aconsequence of this construction, the roller 276 is urged upward to alevel limited by the top wall of the retainers 272 and is yieldable whensubjected to a heavy weight, such as a loaded pallet. Mounted on the topwall 261 of the turntable 260' outwardly from the springloaded roller274 is a helper roller 288 rotatably supported by brackets 290.

The turntable 260 is rotated by a turntable driving unit, generallydesignated 292 (FIGURE 1). The turntable driving unit 292 is mountedupon a base 294 secured to the floor 42 adjacent the periphery of theturntable 260 and includes a drive Wheel 296 mounted on a shaft 298journaled in a vertical housing 299 in the base 294 and having asprocket 360 keyed thereto. The sprocket 300 is driven by a sprocketchain 302 from a sprocket 304 mounted on the output shaft 396 of a speedreducer 308, the input shaft 310 of which is coupled to the motor shaft312 of a rotary hydraulic motor 314.

Empty pallet dispenser Stacked empty pallets P are fed to the turntable260 of the turntable unit 28 by the pallet dispenser 30 located besideit (FIGURES 1, 6, 17 and 18). The pallet dispenser 30 includes a baseframework 320 including a bed frame portion 322 and elevated rollersupporting frames 324 spaced above the bed frame portion 322 on oppositesides thereof. Mounted with their axes of rotation inlongitudinally-spaced relationship on the elevated frame portion 324 aretwo sets of parallel rollers 326 which are freely rotatable. The palletdispenser 30 also has a front wall 328 facing the turntable unit 28 andhaving, adjacent the level of the rollers 326, a horizontally-elongatedopening 330 slightly greater than the width and height of a pallet P soas to enable a single pallet P to be ejected through the opening 330while the front wall 328 above the opening 330 restrains the pallets inthe remainder of the stack of pallets above the pallet being ejected.

Also rising from the base framework 320 is a rear wall 332, andextending between the front wall 328 and rear wall 332 is an adjustableside wall 334. The latter is movable toward and away from the sets ofrollers 326 in order to adjust the pallet dispenser 30 to accommodatedifferent sizes and shapes of pallets. The forward and rearward walls328 and 332 and the side walls 334 are provided with slanting braces336, 338 and 340 respectively, the latter being secured at the lowerrearward ends to bottom members 342. The rear wall 334, with its braces340 and bottom members 342, may be slid backward and forward along thebase frame 320 and bolted into its adjusted position in suitable locatedbolt holes (not shown) in the base frame 320.

Mounted on the bed frame portion 322 of the base frame 320 by means ofcross channel members 344 (FIG- URE 17) by brackets 346, and betweeninwardly-facing longitudinal side members 347 is a reciprocatorydoubleacting hydraulic pallet motor 348 forming the motive portion of apallet ejector, generally designated 350. Reciprocably mounted in thecylinder 352 of the hydraulic motor 348 is the head (not shown) of apiston 354. Mounted on the threaded forward end of the piston 354 is aT-shaped cross head 356 (FIGURES 18 and 19), the longitudinal portion ofwhich is drilled horizontally to receive a pivot shaft 358 upon whichsprockets 360 are rotatably mounted on opposite sides of the cross head356 for travel back and forth therewith. Mounted on the forward end ofthe cross head 356 is a transverse channel bar 362, to the middle ofwhich is secured an angle bracket 364 rotatably supporting a roller 366at the level of the pathway plate 273 so as to roll therealong when thepiston 354 and cross head 356 move outward on their forward stroke, asexplained below in the description of the operation of the invention.

Bolted or otherwise secured to the opposite ends of the transversechannel bar 362 are two elongated longitudinally-extending channel drawbars 368 (FIGURE 18) arranged in laterally-spaced parallel relationshipon opposite sides of the hydraulic motor 250. Rotatably mounted atintervals along the side members 347 by brackets 370 secured thereto arehorizontal guide rollers 372 rotatably on vertical axes and adapted toengage the outer sides of the draw bars 368 through openings 374 in theside members 347. The channel draw bars 368 are supported forlongitudinal reciprocation upon longitudinallyspaced pairs of rollers376 (FIGURE 19) mounted at intervals on horizontal axles 378 supportedby the side members 347 on the inner faces thereof.

Mounted for longitudinal travel along and relatively to the channel drawbars 368 (FIGURE 19) is a pallet ejector carriage, generally designated380, which is provided at the four corners of its base with wheels 382rotatable on horizontal axes and rolling along the inner sides of thechannel draw bars 368. The carriage 380 in the upper portion of itsframe 384 is provided with a horizontal pivot shaft 386 upon which arepivoted laterallyspaced ears 388 welded or otherwise secured to theforward face of a swinging pallet pusher plate 390. The pallet pusherplate 390 during the forward stroke of the carriage 380 remains in anupright position against a back stop 392 on the carriage frame 384. Onthe rearward stroke of the carriage 380, the pusher plate 390 swingsdownward and forward to pass beneath the stack of empty pallets andsprings upward when it passes beyond the lowermost pallet, as explainedbelow.

Anchored as at 394 near the forward upper corners of the carriage frame384 are two parallel forward sprocket chains 396 which pass over andaround the sprockets 360 on the cross head 356 to fixed anchorages 398(FIGURE 17) on the forward channel member 344. From a fixed anchorage400 on the same forward channel member 344, a pair of parallel rearwardsprocket chains 402 extend rearwardly around sprockets 404 rotatablymounted on the inner sides of the channel draw bars 368. The rearwardends of the rearward chains 402 are secured to rearward anchorages 406on the rearward ends of the carriage frame 384 (FIGURE 17). Mounted onthe side members 347 beneath the sprockets 404 are rollers 408. As aconsequence, when hydraulic pressure fluid is supplied to the rearwardend of the hydraulic cylinder 352 and exhausted from the forward endthereof through suitable ports (not shown), the piston 354 movesforward, carrying with it the cross head 356 and its sprockets 360 whichthereby roll along and pull forward the forward sprocket chain 396,causing the carriage wheels 382 to roll along the channel draw bars 368While the draw bars 368 themselves are being pulled forward throughtheir connections to the forward end of the cross head 356. In so doing,the pusher plate 390 pushes a pallet onto the turntable 260. At the sametime, the rearward sprocket chains 402 travel around the sprockets 404as the carriage 380 moves forward relatively to the channel draw bars368 as these in turn move forward relatively to the side members 347.When the hydraulic fluid to the cylinder 352 is reversed, the oppositeor retraction motion of the carriage 380 is effected, and the palletpusher plate swings downward while passing beneath the stack of pallets.Meanwhile, the roller 366 travels along the turntable pathway plate 273(FIGURE 17) during both the forward and return strokes of the piston 354of the hydraulic motor 348. By this arrangement, the pusher plate 390 iscaused to travel twice the length of stroke of the piston 354.

Loaded pallet receiver The loaded pallet receiver 32 (FIGURES l and 6)is in the form of an elevated roller platform 410 formed of channelmembers supported on a framework 412, and carrying elongatedclosely-spaced parallel rollers 414. As explained below in connectionwith the operation of the invention, the ejection of an empty pallet Pfrom the pallet dispenser 30 simultaneously pushes a loaded pallet fromthe turntable 260 onto the roller platform 410, where it is picked up bya conventional fork lift truck T (FIG- URE 1) and by it conveyed to atransported vehicle, such. as a freight car, trailer or truck, or to astorage position, as in a warehouse. If there is a loaded pallet alreadyon the roller platform 410, it is pushed therealong by the arrivingloaded pallet which in turn is being pushed by the empty pallet beingdispensed from the pallet dispenser 30.

Hydraulic system The various motions of the automatic bag palletizer 20are brought about by a hydraulic system, generally designated 420, shownin FIGURE 20, and supplied with hydraulic pressure fiuid from thehydraulic power unit 34 shown diagrammatically in FIGURE 1. Thehydraulic power unit 34 includes a hydraulic fluid tank 422 from which asuction line 424 proceeds through a strainer 426 to the intake of aconstant delivery rotary hydraulic pump 428 driven by an electric motor430 through a coupling 431. The outlet of the hydraulic pump 428discharges hydraulic pressure fluid into a pressure-fluid supply line432 for the remainder of the hydraulic circuit 420 and a hydraulic fluidreturn line 434 carries hydraulic fluid from the remainder of thehydraulic circuit 420 back to the tank 422 by way of a filter 435. Thepressure fluid supply line 432 runs to the inlet ports of eightconventional solenoidally-operated four-way control valves 436, 438,

440, 442, 444, 446, 448 and 450, all of which are operated in bothdirections by solenoids and centered by springs to neutral orno-delivery positions except the valve 444 which in one direction isspring-operated. These four-way valves are conventional, available onthe open market and their details are beyond the scope of the presentinvention. In the apparatus as actually constructed, the lines 432 and434 are connected to manifolds, which have been omitted to simplify thedisclosure.

From the boom lift control valve 440, service lines 452 and 454,including flexible hoses, run to opposite ends of the reciprocating boomlift motors or cylinders 122 and 132 by way of conventional flow controlvalves 456 including check valve and throttle valves for speedregulation. Also included in the lines 452 are pilot check valves 458which automatically close to prevent sagging of the boom when the valve440 is shifted to its neutral position, but which are Opened forcibly bypressure fluid through lines 460 connected to the line 454 during theretraction strokes of the cylinders 122 and 132 in lowering the boomconveyor 86. From the boom extension cylinder control valve 442, servicelines 462 and 464, including flexible hoses, run to opposite ends of thehorizontal reciprocatory hydraulic boom motor or cylinder 146. The line464 contains a conventional needle valve 466 for piston speedregulation. From the boom gate cylinder control valve 444, service lines468 and 470 run to opposite ends of the reciprocatory hydraulicgate-operating motor or cylinder 218, the lines 468 and 470 containingflow control valves 472 similar to the flow control valves 456.

From the pallet dispenser cylinder control valve 446, service lines 474and 476 run to opposite ends of the reciprocatory hydraulic palletdispensing motor or cylinder 348, these lines containing flow controlvalves 478 identical with the flow control valves 456. From the boomcarriage cylinder control valve 448, service lines 480 and 482 run tothe opposite ends of the reciprocatory hydraulic carriage motor orcylinder 102, these lines also containing flow control valves 484identical with the flow control valves 456. From the turntable motorcontrol valve 450, service lines 486 and 488 run to the hydraulic fluidsupply and exhaust ports of the rotary hydraulic turntable motor 284.The line 436 contain a conventional needle valve 490 for motor speedregulation, whereas the line 483 contains a conventional declerationvalve 492 including a check valve 494 and a restriction valve 496operatively connected to a conventional slow-down governor 498 forretarding the motion of the turntable 260 as it nears each of itsstopping points.

From the feeding conveyor motor control valve 436,

service lines 560 and 502 run to the hydraulic fluid supply and exhaustports of the rotary hydraulic bag-feeding conveyor belt motor 70, theline 502 containing a conventional needle valve 504 for motor speedregulation. Similarly, from the boom conveyor motor control valve 438,service lines 506 and 508 run to the hydraulic fluid supply and exhaustports of the rotary hydraulic boom conveyor belt motor 182, the line 508containing a conventional needle valve 510 for motor speed regulation.In order to indicate the pressure in the pressure fluid supply line 432,a branch line 512 leads from the line 432 to a conventional pressuregauge 514 by way of a conventional gauge isolator 516.

Since the hydraulic circuit of FIGURE 20 shows that the various controlvalves are operated by solenoids, it will be evident that theenergization of these solenoids to shift the various valve members, suchas piston valve members, in one direction or the other, requires anelectric circuit. In the automatic bag palletizer 20 as actuallyconstructed, such an electric circuit has been provided, with theenergization of the various solenoids controlled by limit switches and,in the actual stacking operation of each tier of bags, by a steppingswitch or relay which closes a circuit to shift the boom conveyor 86 tothe next higher level when a tier of bags has been laid, in cooperationwith the location of the turntable unit 28. The same circuit contains alimit switch which shuts down the apparatus when the supply of emptypallets in the pallet dispenser 30 becomes depleted to the point wherethere would be no pallet available for ejection on the turntable unit 28to receive the bags dropping from the boom conveyor 86. Furthermore, forthe stacking of bags upon an oblong pallet, as in the five-bag patternof FIGURE 4, additional switches come into operation for actuating thecontrol valve 442 which controls the actuation of the boom cylinder orreciprocatory motor 146.

The electrical circuit referred to above for actuating the variouselements of the hydraulic circuit 420 of FIG- URE 20 is unavoidablycomplicated and, in order to simplify the disclosure, has been omitted.It will be evident that the various switches for controlling the variouscontrol valves 440 to 450 could be actuated in timed relationship, Forthe purpose of simplifying the explanation of the operation of theinvention, such manual switch operation, in cooperation with theautomatic closing and opening of the limit switches mentioned above,will be assumed.

Operation In the operation of the invention, let it be assumed that asupply of empty pallets P has been piled in a stack upon the rollers 326of the elevated frames 324 (FIG- URES 1 and 6) and that a four-bagpattern of bags B is to be stacked. The operator starts the electricmotor 430 to place the hydraulic pump 428 in operation (FIGURE 20) so asto supply hydraulic pressure fluid, such as hydraulic oil underpressure, to the pressure fluid supply line 432 and thence to thevarious control valves 438 to 450. When their respective control valves436 and 438 are suitably shifted, pressure fluid is supplied to thehydraulic motors 70 and 182 of the feeding conveyor 22 and stackingconveyor 26 respectively. Let it further be assumed that the solenoidcontrol valve 448 has been momentarily energized to cause the carriagemotor or cylinder 102 to shift the carriage 88 laterally so as toposition the boom conveyor opening 152 directly over the pallet P on theturntable 260.

Bags B to be stacked are then fed one by one to the outer end of thefeeding conveyor 22, the endless conveyor belt 60 of which carries thebags B downward and at its inner end deposits them upon the lowerendless conveyor belt 16%) of the boom conveyor 86 of the stackingconveyor 26. The motion of the upper course of the conveyor belt carrieseach bag B beneath the upper con veyor belt 192, the lower course ofwhich converges toward the upper course of the lower belt 160. As eachbag passes into the decreasing space between these conveyor belts, asregulated by the adjustment of the pressure roller 200 (FIGURE 12), itis subjected to a flattening action by the compression exerted upon itby the two belts. This flattening action is of importance because itenables many more tiers of bags to be stacked one on top of the otherwithout lateral sliding than with ordinary bags which slide because oftheir naturally rounded shape when not subjected to such flatteningaction.

The bags, thus flattened, are carried forward to a position above theopening 152 (FIGURE 9) where each bag encounters the swinging plate 246(FIGURE 9) which shifts the limit switch 248. This in turn energizes thesolenoid of the control valve 444 which immediately actuates thehydraulic reciprocatory gate motor or cylinder 218 to slide open thegates 236. The bag then drops through the opening 152 onto a pallet P onthe turntable 260 (FIGURE 1), at the same time releasing the limitswitch which immediately tie-energizes the solenoid of the gate controlvalve 444, the spring of which at once shifts the valve member to itsreversed position and causesthe gate motor or cylinder 218 to close thegates 236. The gates 236, however, are maintained in an open position bya timer (not shown) to delay the closing thereof until the bag B hasbeen deposited upon the pallet P on the turntable 260, The same actionhalts the feeder conveyor motor 70 to prevent piling up of bags withinthe boom conveyor 86 and also to initiate and permit the turntablecontrol valve 450 to be energized long enough to cause the rotaryhydraulic motor 284 to rotate the turntable 260 clockwise through a90-degree angle or quarter revolution. As the turntable 260 nears itshalting point, its speed is retarded by the slowdown governor 498 tocause deceleration and thereby prevent the bag or bags B already on thepallet from being shifted by reason of their momentum.

As soon as the turntable 250 of the turntable unit 28 has rotatedthrough this quarter revolution, the solenoid of the turntable motorcontrol valve 450 is de-energized, causing the valve 450 to shift to itsneutral position, halting the turntable 260. The timer then energizesthe feeding conveyor motor 70 to feed another bag B into the boomconveyor 86, where, as before, it is flattened, conveyed to a positionover the gates 236 above the opening 152, and the limit switch operatedby the newly-arriving bag to again open the gates and deposit the secondbag upon the pallet in the second position at right angles to the firstbag (FIGURE 1). The timer just mentioned also delays the operation ofthe feeding conveyor 22 and stacking conveyor 26 until the turntable hasbeen able to rotate 90 degrees at a time to each of its indexedpositions. At the same time, the dropping of each bag actuates astepping switch (not shown) which counts off the number of bagsdeposited upon the pallet P in each tier.

The action of the feeding conveyor 22, stacking conveyor 26 andturntable unit 28 continues in the abovedescribed manner until four bagshave been deposited upon the pallet P of the turntable unit 28,whereupon the stepping switch energizes the control valve 448 of theboom conveyor carriage motor or cylinder 102 and also the control valve440 of the lift motors or cylinders 122 and 132, thereby causing thecarriage motor 102 to move the carriage 88 laterally along its tracks 90and at the same time move the elevator frame 142 and boom conveyor 86upward to the next bag tier level shown in dotted lines at 86 in FIGURES1 and 6. The foregoing cycle of operations then repeats itself, againdepositing four bags in succession, one after another, to form a secondtier, but with the bags B of the second tier overlapping the bags B ofthe first tier, as shown by the contrasting positions of the bags inFIGURES 1 and 2. This overlapping of the bags in effect ties thesuccessive tiers of bags together by their weight and frictionalengagement, thereby preventing sliding relatively to one another whilethe flattening action to which they are subjected in passing through the'boom conveyor 86 also increases the area of contact between the bagsand further aids in preventing slippage.

The turntable 260 of the turntable unit 28 moves through a quarterrevolution after the deposit of each bag, and the boom conveyor 86 ofthe stacking conveyor 26 moves laterally and upward at the completion ofstacking of each tier of bags B, thus oscillating between the solid lineand dotted line positions of the boom conveyor 86 shown in FIGURES 1 and6, but continuing upward on successively heightened levels.

As the boom conveyor 86 rises from tier to tier, it trips a dog at eachtier which actuates a stepping switch (not shown). The latter halts theaction of the boom conveyor 86 of the stacking conveyor 26 when theprescribed number of tiers of bags B has been laid. Meanwhile, as thecarriage 88 shifts back an forth and the boom conveyor 86 rises, theoutlet of the feeding conveyor 22 follows the motions of the inlet ofthe boom conveyor 86 through the pivotal connection 74 between it andthe boom conveyor 86 and by the swinging of its tower frame 44 upon theplatform 40 upon its caster wheels 46.

When the boom conveyor 86 has laid the uppermost tier of the prescribednumber of tiers upon the pal-let P on the turntable 260, the electricalcircuit energizes the solenoid of the pallet ejector control valve 446to admit pressure fluid through the line 474 (FIGURE 20), to therearward end of the pallet motor or cylinder 348 while discharging fluidthrough the line 476 from the forward end thereof. This action causesthe piston 354, cross head 356, rotor 366 and pallet ejector carriage380 to move forward (FIGURES 6 and 17), pushing an empty pallet P offthe bottom of the stack of pallets forwardly over the turntable 260. Atthe same time, the empty pallet P pushes the loaded pallet L off theturntable 260 onto the receiving platform 32 (FIGURE 6) whence it isremoved by a fork lift truck T and conveyed to its place of disposal,such as to a transport vehicle.

As the empty pallet P reaches its proper position upon the turntable260, the ejector carriage 380 actuates a limit switch (not shown) whichreverses the energization of the pallet motor control valve 446 andcauses the retraction of the piston 354 and carriage 380. As the pivotedpallet ejector plate 390 swings beneath the stack of empty pellets inthe pallet dispenser 30, it swings downward around its pivot shaft in aclockwise direction (FIGURE 17) until it passes beyond the rearward edgeof the lowermost pallet P, whereupon it swings upward against the stopmember 392 into its vertical position, ready to eject the next pallet Poff the bottom of the stack onto the turntable 260 in the mannerdescribed above, when called for at the completion of stacking theprescribed number of tiers of bags B upon the previously ejected palletP on the turntable 260.

At the conclusion of the ejection of the loaded pallet P by the nextsucceeding empty pallet P, the electric circuit energizes the stackingconveyor carriage motor control valve 448 and boom conveyor controlvalve 440 to reverse them, causing the carriage 88 to return laterallyand the boom conveyor 86 to descend to their respective startingpositions by the reverse action of the carriage motor 102 and the liftmotors 122 and 132. The cycle of operations then repeats itself in themanner described above until the prescribed number of tiers of bags havebeen deposited upon the pallet P on the turntable 260 and ejection againoccurs by the advancing of a new empty pallet P onto the turntable 260,as described above.

To stack a three-bag pattern (FIGURE 3), a slightly oblong pallet P isrequired instead of the square pallet P employed for stacking thefour-bag pattern described above and shown in FIGURES l, 2, 5 and 6,which did not require the operation of the boom motor control valve 442and boom motor 146. In the stacking of a three-bag pattern, therefore,the boom cylinder control valve 442 is energized to operate the boommotor 146 so as to extend the boom conveyor 86 longitudinally during thestacking of each tier of three bags B in order to compensate for theelongation of the pallet and bag pattern.

The stacking of a five-bag pattern (FIGURE 4) also requires an elongatedor oblong pallet P and likewise requires the energization of the boommotor control valve 442 to cause the boom motor 146 to move the boomconveyor 86 longitudinally and likewise compensate for the elongation ofthe pattern of bags being stacked.

For clearness of disclosure of the invention, in FIG- URE 1 thehydraulic power unit 34 and the turntable driving unit 292 are shown asmoved out into the space between the pallet dispenser 30 and thestacking conveyor 26. In the apparatus 20 as actually constructed, inorder to conserve fioor space, the units 34 and 292 are mounted betweenthe pallet dispensing unit 30.

What I claim is:

1. A filled-bag palletizer, comprising a bag stacker including alaterally-disposed rectilinear guideway, a laterally-movable bag stackercarriage mounted for reciprocation laterally along said guideway,

a bag-stacking conveyor elevator mounted on said carriage for motionupward and downward relatively thereto,

a bag-depositing conveyor mounted on said elevator at right angles tosaid guideway and having a bag outlet,

'3. pallet-receiving turntable mounted for rotation in a substantiallyfixed location at a substantially constant level and disposed beneathsaid outlet of said bagdepositing conveyor in bag-receiving relationshiptherewith,

power-operated means for reciprocating said carriage to and fro alongsaid guideway laterally of said bagdepositing conveyor,

power-operated means for moving said bag-stacking conveyor elevatorupward relatively to said carriage,

power-operated means for rotating said turntable to bring successivesectors thereof into registry with said outlet,

and a prime mover for actuating said means.

2. A filled-bag palletizer, according to claim 1, wherein saidcarriage-reciprocating means includes a hydraulic cylinder with areciprocatory piston operatively connected to said carriage forreciprocation thereof relatively to said guideway and wherein said primemover includes a motordriven hydraulic pump hydraulically connected tosaid cylinder for hydraulic actuation of said piston.

3. A filled-bag palletizer, according to claim 1, wherein saidbag-depositing conveyor includes an elongated frame disposedsubstantially horizontally on said elevator and a substantiallyhorizontal bag-depositing endless conveyor belt mounted longitudinallyon said frame.

4. A filled-bag palletizer, according to claim 1, wherein there isprovided a bag-feeding conveyor having an outlet coupled to saidbag-depositing conveyor and movable laterally to and fro with saidcarriage and stacking conveyor.

5. A filled-bag palletizer, according to claim 3, wherein saidbag-depositing conveyor includes adjustable bag guides disposedlongitudinally of said frame in spaced parallel relationship relativelythereto and movably mounted within said frame on opposite sides of saidlower endless conveyor belt, and also includes means for moving said bagguides toward and away from one another whereby to vary the separationthereof.

6. A filled-bag palletizer, according to claim 1, wherein said elevatorincludes an elongated longitudinal rectilinear guide structure mountedfor upward and downward travel therewith, wherein said bag-depositingconveyor is movably mounted on said guide structure for longitudinaltravel relatively to said elevator toward and away from said turntable,and wherein power-operated means is mounted on said elevator andoperatively connected to said bag-depositing conveyor for effectinglongitudinal travel thereof relatively to said guide structure.

7. A filled-bag palletizer, according to claim 1, wherein anempty-pallet dispenser is disposed in a fixed location adjacent saidfixed location of said turntable with a pallet-supporting surfacedisposed at substantially the same level as the top surface of saidturntable and has means thereon for storing a stack of empty pallets andalso has a power-operated empty-pallet ejector disposed beneath saidpallet-storing means and movable toward and away from said turntable inpallet-supplying rela tionship therewith.

8. A filled-bag palletizer, according to claim 7, wherein said turntablehas a diametral passageway disposed beneath the top surface thereof,wherein said empty-pallet dispenser includes a fluid-pressure cylinderdisposed beneath said empty pallet-storing means in alignment with saidpassageway in one position of rotation of said tumtable and having areciprocable piston with a wheel rotatably mounted on the outer endthereof, wherein said pallet-storing means has a guideway disposedparallel to said cylinder with a tilting pallet pusher slidabletherealong, and wherein an elongated flexible motion-transmitting memberis anchored at one end to said palletstoring means and extends over saidwheel to a connection with said pallet pusher.

9. A filled-bag palletizer, according to claim 4, wherein saidbag-feeding conveyor has its forward end portion pivoted to saidbag-depositing conveyor and has its rearward end portion swingable inresponse to the motion of said carriage and bag-depositing conveyor.

10. A filled-bag palletizer, according to claim 9, wherein an upstandingsupporting structure is pivotally connected to the rearward end portionof said bag-feeding conveyor and has caster wheels thereon permittingfree sliding and swinging motion thereof in response to the lateralreciprocation of said carriage and the upward and downward motion ofsaid bag-depositing conveyor.

11. A filled-bag palletizer, according to claim 6, wherein there isprovided a bag-feeding conveyor having an outlet disposed adjacent theinlet of said bag-depositing conveyor and having its forward portionpivotally coupled to said bag-depositing conveyor, and wherein anupstanding supporting structure is pivotally connected to the rearwardend portion of said bag-feeding conveyor and has caster wheels thereonpermitting free sliding and swinging motion thereof in response to thelateral reciprocation of said carriage and the upward and downwardmotion and longitudinal travel of said bag-depositing conveyor.

References Cited UNITED STATES PATENTS 2,675,928 4/ 1954 Slater 214-62,907,447 10/ 1959 Ofiutt et al 198-165 2,977,002 3/1961 Asp 214-63,143,222 8/1964 Caskie 214-6 3,170,564 2/1965 Gatto 198-165 3,223,25312/1965 Garbe et al 214-6 3,291,010 12/1966 Williamson 214-6 FOREIGNPATENTS 827,324 2/1960 Great Britain. 116,200 1/ 1959 Russia.

GERALD M. FORLENZA, Primary Examiner. I. E. OLDS, R. J. SPAR, AssistantExaminers.

